billable, invoice, paid_status, users, period, period_start, period_end,
show_client, show_invoice, show_paid, show_ip,
show_project, show_start, show_duration, show_cost,
billable, invoice, paid_status, users, period, period_start, period_end,
show_client, show_invoice, show_paid, show_ip,
show_project, show_start, show_duration, show_cost,